尝试使用已销毁的视图：detectChanges

Question

我正在使用Angular Meteor 2创建一个简单的UI。

1）我有一个顶级导航栏组件，其中有一个＆＃39;注销＆＃39;按钮。
2）点击＆＃39;退出＆＃39;按钮它会重定向到“登录” 3）然后我在控制台中看到了这个错误：EXCEPTION: Attempt to use a destroyed view: detectChanges

例外：

EXCEPTION: Attempt to use a destroyed view: detectChanges
browser_adapter.js:77 EXCEPTION: Attempt to use a destroyed view: detectChangesBrowserDomAdapter.logError @ browser_adapter.js:77BrowserDomAdapter.logGroup @ browser_adapter.js:87ExceptionHandler.call @ exception_handler.js:57(anonymous function) @ application_ref.js:265schedulerFn @ async.js:123SafeSubscriber.__tryOrUnsub @ Subscriber.js:225SafeSubscriber.next @ Subscriber.js:174Subscriber._next @ Subscriber.js:124Subscriber.next @ Subscriber.js:88Subject._finalNext @ Subject.js:128Subject._next @ Subject.js:120Subject.next @ Subject.js:77EventEmitter.emit @ async.js:112onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:66ZoneDelegate.handleError @ angular2-polyfills.js:394Zone.runTask @ angular2-polyfills.js:323ZoneTask.invoke @ angular2-polyfills.js:490
browser_adapter.js:77 STACKTRACE:BrowserDomAdapter.logError @ browser_adapter.js:77ExceptionHandler.call @ exception_handler.js:59(anonymous function) @ application_ref.js:265schedulerFn @ async.js:123SafeSubscriber.__tryOrUnsub @ Subscriber.js:225SafeSubscriber.next @ Subscriber.js:174Subscriber._next @ Subscriber.js:124Subscriber.next @ Subscriber.js:88Subject._finalNext @ Subject.js:128Subject._next @ Subject.js:120Subject.next @ Subject.js:77EventEmitter.emit @ async.js:112onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:66ZoneDelegate.handleError @ angular2-polyfills.js:394Zone.runTask @ angular2-polyfills.js:323ZoneTask.invoke @ angular2-polyfills.js:490
browser_adapter.js:77 Error: Attempt to use a destroyed view: detectChanges
    at ViewDestroyedException.BaseException [as constructor] (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:3349:23)
    at new ViewDestroyedException (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:10626:16)
    at DebugAppView.AppView.throwDestroyedError (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:11277:72)
    at DebugAppView.AppView.detectChanges (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:11230:18)
    at DebugAppView.detectChanges (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:11321:44)
    at ViewRef_.detectChanges (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:11011:65)
    at http://localhost:3000/app/app.js?hash=323b1216814e80ed467d95bcda255eb217d7c468:2224:23
    at ZoneDelegate.invokeTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4721:174)
    at Object.onInvokeTask (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:9393:41)
    at ZoneDelegate.invokeTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4721:72)
  -------------   Elapsed: 80 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMacroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4652:47)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4467:37
    at setTimeout (eval at createNamedFn (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5346:24), <anonymous>:3:37)
    at new TopNavbarComponent (http://localhost:3000/app/app.js?hash=323b1216814e80ed467d95bcda255eb217d7c468:2221:9)
    at DebugAppView._View_HomeComponent0.createInternal (HomeComponent.template.js:48:34)
    at DebugAppView.AppView.create (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:11098:21)
  -------------   Elapsed: 2 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at resolvePromise (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4893:29)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4930:25
    at ZoneDelegate.invokeTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4721:174)
    at Object.onInvokeTask (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:9393:41)
  -------------   Elapsed: 0 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at ZoneAwarePromise.then (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5011:25)
    at RuntimeCompiler.resolveComponent (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:40230:14)
    at DynamicComponentLoader_.loadNextToLocation (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:10788:31)
    at RouterOutlet.activate (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:26844:26)
  -------------   Elapsed: 0 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at resolvePromise (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4893:29)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4877:21
    at ZoneDelegate.invoke (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4696:161)
    at Object.onInvoke (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:9402:41)
  -------------   Elapsed: 0 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at resolvePromise (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4893:29)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4877:21
    at ZoneDelegate.invoke (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4696:161)
    at Object.onInvoke (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:9402:41)
  -------------   Elapsed: 0 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at resolvePromise (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4893:29)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4930:25
    at ZoneDelegate.invokeTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4721:174)
    at Object.onInvokeTask (http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:9393:41)
  -------------   Elapsed: 1 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at ZoneAwarePromise.then (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5011:25)
    at http://localhost:3000/packages/modules.js?hash=560db94ec01c0b3e8f499491ffcce7a2ec6c3c5e:26895:53
    at http://localhost:3000/packages/meteor.js?hash=ae8b8affa9680bf9720bd8f7fa112f13a62f71c3:1105:22
    at ZoneDelegate.invoke (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4696:161)
  -------------   Elapsed: 0 ms; At: Wed Jun 15 2016 20:22:09 GMT-0700 (PDT)   -------------  
    at Object.onScheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:5734:30)
    at ZoneDelegate.scheduleTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4704:57)
    at Zone.scheduleMicroTask (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4649:47)
    at scheduleResolveOrReject (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4928:22)
    at resolvePromise (http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4893:29)
    at http://localhost:3000/packages/barbatus_angular2-runtime.js?hash=fda9b73362c52e988ad030102a9f58e4d584cda3:4877:21
    at http://localhost:3000/packages/meteor.js?hash=ae8b8affa9680bf9720bd8f7fa112f13a62f71c3:1105:22BrowserDomAdapter.logError @ browser_adapter.js:77ExceptionHandler.call @ exception_handler.js:60(anonymous function) @ application_ref.js:265schedulerFn @ async.js:123SafeSubscriber.__tryOrUnsub @ Subscriber.js:225SafeSubscriber.next @ Subscriber.js:174Subscriber._next @ Subscriber.js:124Subscriber.next @ Subscriber.js:88Subject._finalNext @ Subject.js:128Subject._next @ Subject.js:120Subject.next @ Subject.js:77EventEmitter.emit @ async.js:112onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:66ZoneDelegate.handleError @ angular2-polyfills.js:394Zone.runTask @ angular2-polyfills.js:323ZoneTask.invoke @ angular2-polyfills.js:490
Subscriber.js:229 Uncaught Attempt to use a destroyed view: detectChanges

顶navbar.component.ts

"use strict";
import {Logger} from "../services/logger.service";
import {Component, ChangeDetectionStrategy, ChangeDetectorRef} from '@angular/core';
import {User} from "../models/user";
import {Router} from '@angular/router-deprecated';
import {UserService} from "../services/user.service";
import {CORE_DIRECTIVES} from '@angular/common';
import {DROPDOWN_DIRECTIVES} from '../../node_modules/ng2-bootstrap';

@Component({
    selector: 'top-navbar',
    templateUrl: 'client/top-navbar/top-navbar.html',
    bindings: [UserService, Logger],
    directives: [CORE_DIRECTIVES, DROPDOWN_DIRECTIVES]
})

export class TopNavbarComponent {

    public user:User;

    public statusDropdown = {
        isOpen: false
    };

    constructor(private userService:UserService, private router:Router, private logger:Logger, private ref:ChangeDetectorRef) {
        setTimeout(() => {
            this.ref.markForCheck();
            this.user = this.userService.getLoggedInUser();
            this.ref.detectChanges();
        }, 0)
    }

    logout() {
        this.logger.warn('[Top Navbar] Logging out the user.');
        localStorage.clear();
        this.router.navigateByUrl('/login');
    }
}

这是我的login.component.ts

"use strict";
import { Component, ChangeDetectionStrategy, ChangeDetectorRef } from '@angular/core';
import { FormBuilder, ControlGroup, Validators } from '@angular/common';
import { MeteorComponent } from 'angular2-meteor';
import { Router } from '@angular/router-deprecated';
import { Logger } from "../services/logger.service";

@Component({
    selector: 'login',
    templateUrl: 'client/login/login.html',
    changeDetection: ChangeDetectionStrategy.OnPush,
    bindings: [Logger]
})

export class LoginComponent extends MeteorComponent {

    loginForm:ControlGroup;
    loginFailed = false;

    constructor(private _logger:Logger, private _router:Router, private ref:ChangeDetectorRef) {
        super();
        let fb = new FormBuilder();
        this.loginForm = fb.group({
            username: ["", Validators.required],
            password: ["", Validators.required]
        });
    }

    login() {


        this.call('authenticateUser', this.loginForm.value.username, this.loginForm.value.password, (err, data) => {

            if (err) {
                this._logger.error(err);

            } else {
                this._logger.info('[Authentication API] ', data);

                if (data.status != 'LOGIN_SUCCESS') {
                    this.loginFailed = true;

                } else {
                    this.loginFailed = false    ;
                    var user = {
                        id: data.id,
                        name: data.name,
                        role: data.role
                    }
                    localStorage.setItem('user', JSON.stringify(user));
                    this._router.navigate(['Home'])
                }
                //This is required for letting Angular know that something has changed.
                //Because this part of code runs out of Angular zone.
                this.ref.markForCheck();  // Mark this component and its children for change detection in next detecting cycle.
                this.ref.detectChanges(); // Trigger change detection.

            }

        });
    }
}

Answer 1

只有对我有用的解决方案是：

if (!this.changeDetectionRef['destroyed']) {
    this.changeDetectionRef.detectChanges();
}

Answer 2

我解决了你的相同问题，但是如果代码更小，我会告诉你可以帮助你解决问题的重点。

问题显然来自detectChanges()，因为更改已完成，并且在组件的销毁阶段调用了方法。

因此，您需要将组件设为implements OnDestroy，然后您需要取消使this.ref.detectChanges()被调用的更改。因此，您的TopNavbarComponent必须类似于：

export class TopNavbarComponent implements OnDestroy {
  // ... your code

  ngOnDestroy() {
    this.cdRef.detach(); // do this

    // for me I was detect changes inside "subscribe" so was enough for me to just unsubscribe;
    // this.authObserver.unsubscribe();
  }
}

P.S：别忘了unsubscribe()你组件中的所有观察者！无论如何你必须这样做，没有取消订阅的订阅可能是包括这个在内的数百个问题的主要原因，请参阅Angular/RxJs When should I unsubscribe from `Subscription`

修改： 我知道网络中的其他解决办法试图通过处理错误本身来解决问题，而最佳做法是了解问题的根源，检查视图是否被破坏是一个很好的解决方案，但最初的原因可能是内存泄漏背后的一个问题，所以问题的根源是需要杀死正在运行的服务而不仅仅是尝试在没有root的情况下杀死错误本身，例如，必须关闭正在运行的订阅（特别是你的自定义订阅）。

因此，为了获得更好的性能需要家务管理，所以并不总是更容易，更快的解决方案是更好的解决方案，如果你隐藏地毯下的污垢并不意味着你打扫房间：）

Answer 3

您可以使用

this.cdref.markForCheck();

而不是 this.cdref.detectChanges(); 在很多情况下。但最好的方法是关注@ Al-Mothafar提示

Answer 4

我的解决方案是取消订阅所有观察员。

订阅：

ngOnInit() {
     this._currentUserSubscription = this._auth.currentUser.subscribe(currentUser => {});
}

使用changeDetector.detach（）取消订阅：

ngOnDestroy() {
    this._currentUserSubscription.unsubscribe();
    this._cdRef.detach();
}

这是我的代码上的necesery，我也必须使用ChangeDetectorRef功能，只有这两件事情是我的代码没有错误。

Answer 5

我解决了：

if (!(<ViewRef>this.cd).destroyed) {
   this.cd.detectChanges();
}

Answer 6

您必须在变量中获取订阅者的值，并使用相同的var取消订阅。请参考以下相同的代码

import { Component, OnInit, ChangeDetectionStrategy, ChangeDetectorRef, OnDestroy } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import { Cartservice } from './../cartservice.service';
import { ISubscription } from 'rxjs/Subscription';



export class CartComponent implements OnInit, OnDestroy {

private subscription: ISubscription;
ngOnInit() {
    this.subscription = this.cartservice.productsObservable.subscribe(cart => {
      this.cartProducts = cart.products;
      this.cartTotal = cart.cartTotal;
      this.changeDetectorRef.detectChanges();
    });
  }

 ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

请注意，我已取消订阅ngOnDestroy（）方法的更改。

Answer 7

只需在OnDestroy生命周期挂钩上分离ChangeDetectorRef，并在执行detectChanges方法之前检查ChangeDetectorRef是否已销毁

    constructor(private cd: ChangeDetectorRef){}

    someFunction(){
      if(!this.cd['destroyed']){
        this.cd.detectChanges();
      }
    }

    ngOnDestroy(){
      this.cd.detach();
    }

Answer 8

在我的情况下，这是一个错误管理组件配置和编译的异步测试设置的问题。

1. 失败的代码使用TypeScript Async/Await
进行了一个单一的异步beforeEach（）
2. 为了让它正常工作，我使用了两个beforeEach（），其中第一个使用Angular's async()和second beforeEach() is sync处理异步。

代码导致错误..

beforeEach(async () => {
    await TestBed.configureTestingModule({
        imports: [
            BrowserAnimationsModule
        ],
        providers: [
            { provide: ComponentFixtureAutoDetect, useValue: true },
            { provide: OptionsService, useValue: optionServiceMock },
        ],
        declarations: [EventLogFilterComponent],
        schemas: [NO_ERRORS_SCHEMA]
    }).compileComponents();
    fixture = TestBed.createComponent(EventLogFilterComponent);
    component = fixture.componentInstance;
    optionsService = TestBed.get(OptionsService);
    component.filterElem = jasmine.createSpyObj('filterElem', ['close']);
    fixture.detectChanges();
});

修复了......

beforeEach(async(() => {
    TestBed.configureTestingModule({
        imports: [
            BrowserAnimationsModule
        ],
        providers: [
            { provide: ComponentFixtureAutoDetect, useValue: true },
            { provide: OptionsService, useValue: optionServiceMock },
        ],
        declarations: [EventLogFilterComponent],
        schemas: [NO_ERRORS_SCHEMA]
    }).compileComponents();
}));

beforeEach(() => {
    fixture = TestBed.createComponent(EventLogFilterComponent);
    component = fixture.componentInstance;
    optionsService = TestBed.get(OptionsService);
    component.filterElem = jasmine.createSpyObj('filterElem', ['close']);
    fixture.detectChanges();
});

Answer 9

与具体问题没什么关系，但我通过谷歌搜索相同的错误来到这里，所以我将分享我的解决方法。问题是我在fixture.detectChanges()内调用了fixture.whenStable().then(() => {})而没有将测试包含在async函数中。

在：

it('should...', () => {
  fixture.whenStable().then(() => {
    fixture.detectChanges();
  });
});

在：

it('should...', async(() => {
  fixture.whenStable().then(() => {
    fixture.detectChanges();
  });
}));

Answer 10

这个答案对我没有帮助。我找到了其他解决方案。

子组件具有单击关闭按钮时触发的输出

    RecyclerViewHolderobject.changeColor(Color.BLACK)

&& 34; hideChildComponent（）＆＃34;父组件中的方法检测到更改。

<child-component
    *ngIf="childComponentIsShown"
    (formCloseEmitter)="hideChildComponent()"
></child-component>

希望这会对某人有所帮助。

Answer 11

简单：

FIRST_VALUE()

Answer 12

当我尝试使用NgbActiveModal打开模态对话框时，我的原因发生了。显然从自己的.dismiss()调用ngOnInit()会导致此问题。

export class MyModal {
    constructor(private modalInstance: NgbActiveModal) {
    }

    ngOnInit() {
       if (foo) this.modalInstance.dismiss();
    }

解决方法是在解雇前等待。

if (foo) setTimeout(() => this.modalInstance.dismiss());

Answer 13

对我来说，唯一有效的解决方案如下：

ngOnInit() {
    if (this.destroyedComponent) this.changeDetector.reattach();

this.destroyedComponent = false;
this.subscription = this.reactive.channel$.subscribe(msg => {
  switch (msg) {
    case "config:new_data":
      if (!this.destroyedComponent) {
        this.table.initTable();
        this.changeDetector.detectChanges();
      }
  }
})
}

ngOnDestroy() {
   this.subscription = null;
   this.destroyedComponent = true;
   this.changeDetector.detach();
}

说明：

1. 如果该组件已被严重破坏，请重新安装检测器。
2. 将先前的标志设置为虚假值。
3. 保存RxJs订阅，并在其中设置所需的逻辑。
4. 将该逻辑包装在一个条件中，该条件检查该组件是否已被先前声明的标志设置为已销毁。
5. 对块内的更改执行所需的检测。
6. 设置ngOnDestroy（）方法并取消订阅，将destroyComponent标记设置为真实值，然后分离changeDetector。

Answer 14

为避免此错误，请尝试通过以下方法包装模型更改代码，而不是调用detectChanges（）：

this.ngZone.run(() => {
      ...
});